Rimonabant improves a wide variety of cardiovascular and metabolic risk factors in overweight or obese patients with abnormal blood lipid profiles, according to data from the RIO-Lipids trial published in the November 17 issue of the New England Journal of Medicine.

The trial evaluated rimonabant in overweight or obese patients with abnormal blood lipids (high triglycerides and/or high total cholesterol/high-density-cholesterol ratios).

Patients who took rimonabant 20mg daily had a significant improvement in a range of cardiometabolic risk factors that may contribute to type 2 diabetes and heart disease.

Improvements included a reduction in triglyceride levels and an increase in high-density cholesterol. There were also reductions in waist circumference and body weight, improved glucose tolerance, and decreased blood pressure.

Significant improvements were also seen in emerging risk markers, including an increase in adiponectin, a protein associated with reduced risk of diabetes and heart disease and a reduction in C-reactive protein.

Importantly, statistical analysis suggested that the increases in adiponectin observed in the trial were beyond improvements that could be attributed to weight loss alone, raising the potential of a direct effect of rimonabant on this risk marker.

"One of the more noteworthy findings of the RIO-Lipids trial is the evidence that rimonabant, the first selective CB 1 Blocker, through its effects in peripheral tissues significantly increases adiponectin levels beyond what could be expected from weight loss alone. This provides evidence for the potential of rimonabant to improve multiple cardiometabolic risk factors in patients with excess abdominal adiposity and other comorbidities such as diabetes or dyslipidemia," said Jean-Pierre Despres, PhD, Director of Research, Quebec Heart Institute, Laval Hospital Research Center, Sainte-Foy, Quebec, and Principal Investigator of the RIO- Lipids trial.

At one year, patients treated with rimonabant achieved a 12.6 percent reduction in triglyceride levels compared with 0.2 percent for patients on placebo. This was accompanied by a 19.1 percent increase in high-density cholesterol for rimonabant compared with 11.0 percent for placebo. This change was correlated with increases in adiponectin seen in the study and suggests a key role of the latter in explaining weight loss-independent effects of rimonabant. Relative to placebo, total cholesterol and low-density cholesterol levels remained unchanged although, low-density particle size shifted toward a healthier, less atherogenic profile.

Patients on rimonabant had an average decrease in waist circumference of 7.1 cm versus 2.4 cm for placebo. Consistent with findings of other RIO trials, patients on rimonabant 20mg/day lost an average of 6.9 kg compared with 1.5 kg for placebo. Further, 58.4 percent of patients treated with rimonabant lost more than 5 percent body weight compared with 19.5 percent of placebo. Moreover, 32.6 percent of patients on rimonabant lost more than 10 percent body weight compared with 7.2 percent of patients on placebo.

Even in this non-diabetic population, rimonabant led to decreased insulin levels and improvements in glucose tolerance, both important predictors for development of type 2 diabetes. Moreover, decreases in both systolic and diastolic blood pressure were seen in the rimonabant arm.

These cardiometabolic risk factors -- abdominal obesity, high triglycerides, low high-density cholesterol, elevated blood glucose, and hypertension -- often cluster together. In this study, 52.9 percent of patients treated with rimonabant and 51.9 percent of patients on placebo met criteria for metabolic syndrome. By the end of the study, the prevalence of the syndrome fell to 25.8 percent in patients on rimonabant compared with 41 percent of patients on placebo.